2024 Keystone Montana 3121RL vs 2025 Keystone Cougar 354FLS

Detailed Comparison

Comparing the 2024 Keystone Montana 3121RL to the 2025 Keystone Cougar 354FLS reveals some interesting trade-offs that could influence your buying decision.

Starting with size, the Keystone Montana 3121RL measures 28.0 ft long and tips the scales at 12,000 lbs dry weight. The Keystone Cougar 354FLS comes in at 34.0 ft with a dry weight of 14,200 lbs. That gives the Keystone Cougar 354FLS roughly 6.0 extra feet of length.

Capacity-wise, expect to sleep 5 in the Keystone Montana 3121RL versus 6 in the Keystone Cougar 354FLS. With 1 and 4 slide-outs respectively, the parked floor plans differ significantly.

Tank capacities are a key off-grid consideration. The Keystone Montana 3121RL carries 93 gal of fresh water, 48 gal gray, and 39 gal black. The Keystone Cougar 354FLS offers 100 gal fresh, 45 gal gray, and 46 gal black. The Keystone Cougar 354FLS has the edge for extended dry camping.

Budget-wise, the Keystone Montana 3121RL is listed at $66,000 compared to $68,000 for the Keystone Cougar 354FLS.

For family camping trips, the larger floor plan and additional berths make a real difference. For boondocking, the model with superior solar and battery setup will keep you comfortable off the grid longer. If you're going full-time, the larger tanks and more robust build quality matter enormously.

Ultimately, both rigs have their merits — test drive each one and see which floor plan speaks to your lifestyle.